Jazzmyn,
Your quilt top is beautiful! I love bargello quilts, just haven't made one yet.
When you get ready for the borders, measure your quilt top through the center; that's the measurement for the border strips. Pin your borders on starting in the center of both the border fabric and the quilt top; ease as needed so that your quilt top will be square when you're done. I sew the top and bottom on first, measure again for the side borders and then sew those on.
I cut my backing fabric 5" larger than the top all around and the batting is cut the same size as the backing.
A wonderful book for beginners is: "Quilter's Complete Guide" by Marianne Fons and Liz Porter. It has lots of great instructions and photos.
sewing happily in Texas,
Sharon W.